Propulsion of vessels.



PATBNTD MAY 5, 1908.

VUNO. 886,850.

G. .PERTOIZ PROPULSION OP VESSE APPLICATION FILED JAN. 27,

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No. 886,850., PATENTED MAY 5, 1908. G. PBRTOT'.

vPRoPULsIoN 0F' VEssBLs. APPLICATION FILED J'AN.2I,1908.

2 SHEETS-'SHEET z.

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' ship inclined respectively to the right and GIOVANNI PERTOT,

OF MILAN, ITALY.

PROPULSION OF VESSELS.

Specification of Letters Patent.

Patented May 5, 1908.

Application led January 27, 1906. Serial No. 298,245.

T o all whom it may concern:

Be it known that I, GIOVANNI PERTOT, a subject of the King of Italy, residing at Milan, in the Province of Milan, Kingdom of Italy, have invented certain new and useful Improvements in Propulsion of Vessels, of which the following is a specification.

My invention has for its object to permit a very high rate of speed in ships propelled by screws.

IfIeretofore in ships provided with the ordinary reciprocating steam engines, it was impossible to give to the screw propeller such high speed as could be given by the adoption of steam turbines. But in a ship having the screw propeller placed at the stern in the ordinary way, should this be turned at the highest speed that is possible with the adoption of steam turbines, the result would be the sinking of the ship. In fact a tremendous resistance will be encountered on the bow as the ship is proceeding, and the dashing of the bow against the water, will raise waves so high as to submerge the ship. To avoid these accidents, I provide the ship with a screw propeller placed under the keel, near the bow of the ship, at a distance from the prow, of about the length of the ship.

The shaft of the screw propeller is inclined so that it forms an angle with the horizontal, which angle may be larger or smaller, according to the size of the ship, the form of the keel, etc.

I prefer as a rule, to have two screw propellers, instead of one only, placed symmetrically to the right and left of the frame of the ship.

If the tonnage of the ship is high, If* put even four or more screw propellers in two rows symmetrically as described.

Inthe accompanying drawings: Figure 1 is an endwise view of a ship, with screw propellers fitted to it in the described way, Figs. 2 & 3 are similar views, showing the to the left of the vertical, Fig. 4 is a longitudinal view of a ship, Fig. 5 is a longitudinal view of a ship fitted with 4 screw propellers.

In the said figures.: (a) is the screw propeller, (t) is the shaft of the screw propeller, (c) is the water tank, (d) is the steam tur bine, (e) is the steam pipe to the turbine, (f) is the water discharge pipe, (g) is the steam boiler, (h) is the upper portion of the i vessel, (i) is the rudder, (l) is the floating line.

As shown in the drawings whenthe ship is provided with many screw propellers, I prefer to work each of them with a special steam turbine, although they could be also worked with a suitable transmission of power, by one central reciprocating steam engine or steam turbine.

In large ships the screw propellers may be placed-in a suitable concavity of the keel;-

in small ships, this will not be necessary.

The special location of the screw propeller and the inclination given to its shaft, as described, has the result that the reaction of water on ship, .will have its point of application near the bow, and will have a direction inclined to the horizontal. It may therefore be resolved into two component forces, one in a horizontal and the other in a vertical direction. The former pushes the ship through the water; and the other has the effect of raising the prow of the ship in such a way, that a much less resistance will be felt on it, with the result that a high speed may safely be carried.

The propeller shafts are most advantageously inclined to the horizontal within a few degrees only at most of an angle of forty five degrees, as shown; since as I have discovered the speed of the ship, under the same conditions of the application of the power, i

diminishes the more the inclination substantially deviates from said' angle in the direction either of zero or degrees. They are located in vertical planes parallel with the longitudinal aXis of the vessel.

My invention may be applied to any kind of ship, and also to torpedoes. It could be, with equally good results, applied to dirigible balloons, by placing underneath in the same way as shown for ships, one or two screw propellers, or two rows of these, with such an inclination and at such distance from the prow, as substantially shown above.

In the hereinafter written claims, the word vessel applies primarily to a vessel navigating the water at the surface, but by eXtension it applies also (l) to a submarine vessel, and (2) to a vessel (as a balloon, for example) for navigating the air.

I claim:

l. A navigable vessel having a screw propeller located in a recess at a distance'froml the bow equal to about one-third the vessels length and mounted on the rear end of a drivi g shaft which is inclined to the'horizontal in a vertical plane in the direction of the vessels longitudinal axis, the location of the propeller With respect to the recess allowing the propeller blades to act mainly on the fluid outside of the recess, substantially as described.

2. A navigable vessel vhaving recesses in the bottom thereof in separate recesses on opposite sides of the keel at a distance from the bow equal to about one-third the vessels length, and propellers mounted on the rear ends of driving shafts Which are inclined to the horizontal in vertical planes parallel with the longitudinal axis of the vessel, the propellers turning in part Within said recesses but acting mainly on the outside fluid, substantially as described.

In testimony, that I claim the foregoing as my invention, I have signed my name in presence of two subscribing Witnesses.

GIOVANNI PERTOT. WTitnesses MICHELE DE DRAGO, SVEND II. SALOMON` 

